Is the utility software that can be used to keep your files protected from other by encryption. Data stored in encrypted volume cannot be accessed without using the correct password. Even one can store data in hidden partition in the created partition. Works with Windows 7/Vista/XP/2000, Mac OS X and Linux.
How True Crypt Works
 We create encryted File System Volume. And specify hashing algorithm for ecncryption. We set password for the same.
 The created volume gets space from existing memory in HDD. And the volume is mounted as separate drive on system.
 While getting data from the mounted drive data gets decrypted on-fly and while copying the data gets encrypted on-fly. Decrypted data gets stored on RAM temporarily. No extra burden on RAM as decryption is done in portion.
 You can dismount the drive after your work complete. If computer gets turn off all mounted drives get dismounted itself.
More About True Crypt
(1) To download software go to link: http://www.truecrypt.org/downloads
(2) When you install the software, it shows you the .pdf file containing details for how to use the software effectively.
(3) It's safe to download and use it as it automatically creates a restore point in your system.
Just give it try. I liked it very much to hide secret files. And if someone gets access to system and get that file he/she can't do anything with that except deleting it.
I have tried to provide correct information as I have used it. However I'll not be responsible for any type of damage to your system. For any help do write back t0 firstname.lastname@example.org